Effectively Improve the Astaxanthin Production by Combined Additives Regulating Different Metabolic Nodes in Phaffia rhodozyma

Astaxanthin is an important natural resource that is widely found in marine environments. Metabolic regulation is an effective method for improving astaxanthin production in Phaffia rhodozyma. Most studies have focused on single regulators, which have limited effects. In this study, 16 metabolic regulators were screened to improve astaxanthin production in high-yield and wild-type strains. Fluconazol and glutamic acid increased astaxanthin volumetric yield in MVP14 by 25.8 and 30.9%, respectively, while ethanol increased astaxanthin volumetric yield in DSM626, 29.3%. Furthermore, six additives that inhibit the competing pathways and promote the main pathway for astaxanthin synthesis were selected for combination treatment. We found that the optimal combination was penicillin, ethanol, triclosan, and fluconazol, which increased astaxanthin cell yield by 51%. Therefore, we suggest that simultaneously promoting the master pathways (mevalonate) and inhibiting competing pathways (fatty acid synthesis and ergosterol) is the best strategy to improve astaxanthin cell yield. Moreover, regulators of the biomass pathway should be avoided to improve cell yield. This study provides a technical basis for the utilisation of astaxanthin in P. rhodozyma.

Methodological approaches to integrated quality assessment and baking characteristics of wheat during storage

Цель данной статьи - совершенствование методологии комплексной оценки хлебопекарных свойств продовольственной пшеницы и хлебопекарной муки. Учеными ВНИИ зерна предложена единая система комплексной оценки качества хлебопекарной пшеницы и муки, которая предполагает объединить все этапы производства и переработки пшеницы на единых принципах: наличие единого критерия оценки качества зерна и зернопродуктов, начиная с селекции и семеноводства, выращивания зерна и заканчивая мукомольным и хлебопекарным производством; единая система классификаций, основанная на единых показателях хлебопекарных свойств и взаимоувязанных норм по ним в классификациях на семена, товарное зерно, муку, хлеб; единые методы оценки хлебопекарных свойств зерна и зернопродуктов на различных этапах производства и переработки пшеницы; единый комплекс приборов и лабораторного оборудования для оценки качества зерна и муки, в том числе по показателям хлеба, на различных этапах производства и переработки пшеницы. В настоящее время с помощью компьютерной техники и современного программного обеспечения выявлен минимальный комплекс показателей, обеспечивающих объективную характеристику хлебопекарных свойств пшеницы, который включает «количество клейковины», «качество клейковины» и «число падения» при обязательном условии оценки их в комплексе. Эти показатели хорошо коррелируют с качеством хлеба, в частности с объемным выходом хлеба: чем выше количество клейковины, крепче качество клейковины, ниже число падения, тем больше объем хлеба. В этой связи для получения хлеба необходимого качества большое значение имеет установление верхнего значения для показателя «число падения», который по предложенным квалификационным нормам равен 340 с. The purpose of this article is to improve the methodology for a comprehensive assessment of the baking properties of food wheat and bread flour. Scientists from the All-Russian Grain Research Institute have proposed a unified system of comprehensive assessment of the quality of bakery wheat and flour, which involves combining all stages of wheat production and processing on the same principles: availability of a single criterion for assessing the quality of grain and grain products, starting with breeding and seed production, growing grain, and ending with flour and bakery production; a unified system of classifications based on uniform indicators of baking properties and interrelated norms for them in classifications for seeds, commercial grain, flour, bread; uniform methods for assessing the baking properties of grain and grain products at various stages of production and processing of wheat; a unified set of instruments and laboratory equipment for assessing the quality of grain and flour, including the indicators of bread at various stages of production and processing of wheat. At present, with the help of computer technology and modern software, a minimum set of indicators has been identified that provide an objective characterization of the baking properties of wheat, which includes the «amount of gluten», «quality of gluten» and «falling number» with the obligatory condition of their assessment in the complex. These indicators correlate well with the quality of bread, in particular, with the volumetric yield of bread: the higher the amount of gluten, the stronger the quality of the gluten, the lower the falling number, the larger the volume of bread. In this regard, in order to obtain bread of the required quality, it is of great importance to establish the upper value for the «falling number» indicator, which, according to the proposed qualification standards, is 340 с.

Evaluation of consumer properties of grain of spring soft wheat selection lines

The article presents the results of studying 10 numbers of competitive variety testing in the Ryazan region in order to identify new breeding lines of spring soft wheat with high technological and baking indicators. The assessment carried out in 2017-2019 revealed that according to the yield the breeding lines 1036-09Н21 and 898-09Н125 exceeded the Agata standard variety (4.47 t/ha) by 0.61 t/ha and 0.48 t ha, respectively (LSD05 = 0.34 t/ha). Over the years of the research, the variety samples formed a glassy well-made grain with the nature of 770-817 g/l, with the protein content in the grain of 14.1-16.0 % and the mass fraction of raw gluten in the flour of 29-41 % of high quality (IDK 45-75 units). The greatest potential for protein accumulation in grain was possessed by the varieties Agata, RIMA, lines 539-10H163, 543-13H163 – 16.8-19.3 %. On the average, the falling number was relatively high 264-331 s, corresponding for wheat of the first and second classes. Lines 543-13H163, 539-10H163 and 898-09H125 exceeded the standard in terms of sedimentation value by 15-17 ml or 35-40 %. The specific work of the dough deformation in the samples varied from 305 a.u. up to 421 a.u., corresponding to the standards of strong or valuable wheat. It has been established that the volumetric yield of bread for lines 509-13Н148, 539-10Н163 and 543-13Н163 was 1633-1647 cm3, higher than the Agat standard variety by 16-17 %. Valuable material 539-10N163 and 898-09N125 that meets the requirements of flour-grinding and bakery enterprises has been developed. It has the following varietal characteristics: grain nature is more than 800 g/l, protein content in grain is 15-16 %, gluten in flour is 33-34 %, with the sedimentation indicator of 58-60 ml, the deformation energy of the dough of 389-421 a.u, the volumetric bread yield of 1523-1647 cm3.

Scale-up fermentation of Escherichia coli for the production of recombinant endoglucanase from Clostridium thermocellum

Endoglucanase (EC 3.2.1.4) catalysing the hydrolysis of β-1.4-glycosidic linkage of cellulose molecules is an enzyme of tremendous industrial importance. The present study describes a response surface methodology based predicted model to deduce a set of fermentation conditions for optimum growth and activity of recombinant endoglucanase in E. coli BL21 (DE3). Numerous significant parameters including fermentation media composition, temperature (Celsius), pH and agitation rate (rpm) were analysed systemically by employing central composite design. This effort reports highly efficient recombinant endoglucanase overproduction (6.9 gl−1 of biomass) with 30% expression by E. coli in modified M9NG media incubated at 37 °C and pH 7 agitated at 200 rpm. Addition of 3 mM glucose and 24 mM glycerol in the M9NG media has shown positive effect on the enzyme yield and activity. The CMCase activity experimentally estimated was found to be 1185 U/mg with the optimized parameters. The outcomes of both the responses by the predicted quadratic model were found in consensus with the obtained values. Our results well depicted the favourable conditions to further scale-up the volumetric yield of other relevant recombinant enzymes and proteins.

Harvesting Design by Capital Return

One can suspect that capital return rate in forestry can be maximized by growing trees experiencing a value-adding assortment transition. Such a situation may or may not endure. We investigate the financial feasibility of a few harvesting schedules for a semi-shade-tolerant tree species. Some example stands have experienced commercial low thinning, whereas others have experienced young stand cleaning only. High thinning is computationally combined with quality thinning, and further growth of trees is estimated using an applicable growth model. High capital return rates are gained by diameter-limit cutting to the transition diameter between pulpwood and sawlogs. Repeated thinnings lead to a reduction in the capitalization during several decades, the system approaching a stationary state. The transient forest stands investigated show a significant excess capital return, in relation to the stationary state, and this excess return is due to transient tree size distribution. Correspondingly, capital return rate gained in rotation forestry is somewhat higher than that of stationary continuous-cover forestry, and the volumetric yield is much higher. The productive capacity of stands previously thinned from below has been apparently ruined by that treatment.

Thinning Schedules for Spruce Stands

We investigate financial feasibility of a few thinning schedules for spruce stands. Some example stands have previously experienced commercial low thinning, whereas others young stand cleaning only. High thinning is combined with quality thinning, and further growth of trees is estimated using a Norwegian growth model. High capital return rates are gained by diameter-limit cutting to the transition diameter between pulpwood and sawlogs. Repeated thinnings lead to reduction in the capitalization during several decades, the system approaching a stationary state. The transient forest stands investigated shown a significant excess capital return, in relation to the stationary state, and this excess return is due to transient tree size distribution. Correspondingly, capital return rate gained in rotation forestry is somewhat higher than that of stationary continuous-cover forestry, and the volumetric yield is much higher. The productive capacity of stands previously thinned from below apparently has been ruined by that treatment.

Optimization of Hydrothermal and Diluted Acid Pretreatments of Tunisian Luffa cylindrica (L.) Fibers for 2G Bioethanol Production through the Cubic Central Composite Experimental Design CCD: Response Surface Methodology

This paper opens up a new issue dealing with Luffa cylindrica (LC) lignocellulosic biomass recovery in order to produce 2G bioethanol. LC fibers are composed of three principal fractions, namely, α-cellulose (45.80% ± 1.3), hemicelluloses (20.76% ± 0.3), and lignins (13.15% ± 0.6). The optimization of LC fibers hydrothermal and diluted acid pretreatments duration and temperature were achieved through the cubic central composite experimental design CCD. The pretreatments optimization was monitored via the determination of reducing sugars. Then, the 2G bioethanol process feasibility was tested by means of three successive steps, namely, LC fibers hydrothermal pretreatment performed at 96°C during 54 minutes, enzymatic saccharification carried out by means of a commercial enzyme AP2, and the alcoholic fermentation fulfilled with Saccharomyces cerevisiae. LC fibers hydrothermal pretreatment liberated 33.55 g/kg of reducing sugars. Enzymatic hydrolysis allowed achieving 59.4 g/kg of reducing sugars. The conversion yield of reducing sugar to ethanol was 88.66%. After the distillation step, concentration of ethanol was 1.58% with a volumetric yield about 70%.